Weizhao Cai1, Jiangang He2, Hao Li3, Rong Zhang1, Dongzhou Zhang4, Duck Young Chung3, Tushar Bhowmick1, Christopher Wolverton5, Mercouri G Kanatzidis6,7, Shanti Deemyad8. 1. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA. 2. Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. jiangang2020@gmail.com. 3. Materials Science Division, Argonne National Laboratory, Lemont, IL, USA. 4. PX2, Hawaii Institute of Geophysics and Planetology, University of Hawaii at Manoa, Honolulu, HI, USA. 5. Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. 6. Materials Science Division, Argonne National Laboratory, Lemont, IL, USA. m-kanatzidis@northwestern.edu. 7. Department of Chemistry, Northwestern University, Evanston, IL, USA. m-kanatzidis@northwestern.edu. 8. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA. Deemyad@physics.utah.edu.
Abstract
Ferroelectricity is typically suppressed under hydrostatic compression because the short-range repulsions, which favor the nonpolar phase, increase more rapidly than the long-range interactions, which prefer the ferroelectric phase. Here, based on single-crystal X-ray diffraction and density-functional theory, we provide evidence of a ferroelectric-like transition from phase I213 to R3 induced by pressure in two isostructural defect antiperovskites Hg3Te2Cl2 (15.5 GPa) and Hg3Te2Br2 (17.5 GPa). First-principles calculations show that this transition is attributed to pressure-induced softening of the infrared phonon mode Γ4, similar to the archetypal ferroelectric material BaTiO3 at ambient pressure. Additionally, we observe a gradual band-gap closing from ~2.5 eV to metallic-like state of Hg3Te2Br2 with an unexpectedly stable R3 phase even after semiconductor-to-metal transition. This study demonstrates the possibility of emergence of polar metal under pressure in this class of materials and establishes the possibility of pressure-induced ferroelectric-like transition in perovskite-related systems.
Ferroelectricity is typically suppressed under hydrostapan class="Chemical">tic compression because tn>an class="Chemical">he short-range repulsions, which favor the nonpolar phase, increase more rapidly than the long-range interactions, which prefer the ferroelectric phase. Here, based on single-crystal X-ray diffraction and density-functional theory, we provide evidence of a ferroelectric-like transition from phase I213 to R3 induced by pressure in two isostructural defect antiperovskites Hg3Te2Cl2 (15.5 GPa) and Hg3Te2Br2 (17.5 GPa). First-principles calculations show that this transition is attributed to pressure-induced softening of the infrared phonon mode Γ4, similar to the archetypal ferroelectric material BaTiO3 at ambient pressure. Additionally, we observe a gradual band-gap closing from ~2.5 eV to metallic-like state of Hg3Te2Br2 with an unexpectedly stable R3 phase even after semiconductor-to-metal transition. This study demonstrates the possibility of emergence of polar metal under pressure in this class of materials and establishes the possibility of pressure-induced ferroelectric-like transition in perovskite-related systems.
Authors: Jin Wang; Ben Wylie-van Eerd; Tomas Sluka; Cosmin Sandu; Marco Cantoni; Xian-Kui Wei; Alexander Kvasov; Leo John McGilly; Pascale Gemeiner; Brahim Dkhil; Alexander Tagantsev; Joe Trodahl; Nava Setter Journal: Nat Mater Date: 2015-08-10 Impact factor: 43.841
Authors: Muhtar Ahart; Maddury Somayazulu; R E Cohen; P Ganesh; Przemyslaw Dera; Ho-kwang Mao; Russell J Hemley; Yang Ren; Peter Liermann; Zhigang Wu Journal: Nature Date: 2008-01-31 Impact factor: 49.962
Authors: P-E Janolin; P Bouvier; J Kreisel; P A Thomas; I A Kornev; L Bellaiche; W Crichton; M Hanfland; B Dkhil Journal: Phys Rev Lett Date: 2008-12-02 Impact factor: 9.161